Electrical connector with cam action

ABSTRACT

A solderless connector is disclosed for force-free insertion and removal of contact terminals of electrical devices. A plurality of contact elements are provided having split resilient and spaced diverging contact segments which are slidably mounted through apertures in a controllably reciprocable cam plate actuable for selective positioning along the extension of the contact segments. The contact segments diverge to an open position from a common bight adjacent a support to which the contact elements are mounted. When the cam plate is actuated to the upper position of the contact segments, they are deflected inwardly to bring them into contact with terminal elements of a device inserted in the connector. When the cam plate is returned to the lower position of the contact segments, they are returned to the open position for removal and insertion of the devices.

U United States Patent [111 3,5 ,905

[72] Inventor Theoharis Kehagioglou 3,366,916 1/1968 Oktay 339/74 A l N s r FOREIGN PATENTS [2 pp o. Filed Nov. 19 1968 654,455 12/1937 Germany 339/74 [45] Patented Mar. 9, 1971 Primary ExaminerMarvin A. Champion [73] Assignee International Business Machine Assistant Examiner-Joseph l-l. McGlynn C ti Attorneys-Hamlin, Jancin and Henry Powers Armonk,N.Y.

[54] ELECTRICAL CONNECTOR WITH CAM ACTON ABSTRAQT: A solderless connector is disclosed for forcefree insertion and removal of contact terminals of electrical 6 Claims, 10 Drawing Figs.

devices. A plurality of contact elements are provided having [52] US. Cl. 339/75, split resilient and spaced diverging ontact egments which 3 9/l 339/ 176 are slidably mounted through apertures in a controllably [51] Int. H01! 13/62 reciprocable cam plate actuable for selective positioning 0f 75, along the extension of the ontact segments The ontact seg.

176, ments diverge to an open position from a common bight adjacent a support to which the contact elements are mounted. [56] References CM When the cam plate is actuated to the upper position of the U IT STATES PATENTS contact segments, they are deflected inwardly to bring them 1,667,485 4/1928 MacDonald 339/273 into contact with terminal elements of a device inserted in the 2,711,523 6/ 1955 Willis 339/253 connector. When the cam plate is returned to the lower posi- 2,857,577 10/1958 Vanderpool 339/ 17 tion of the contact segments, they are returned to the open 2,978,666 4/1961 McGregor 339/17L position for removal and insertion of the devices.

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Pa1zented March 9, 1971 2 Sheets-Sheet 1 11001111111111 FIG. 1 1

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flmmlamlmaa 6A ,13AT\ I 0 4 9" w/ 7 1 mm 52 l 6 o0 15A 17A 10 F164 A T TORNE Y I ELECTRICAL CONNECTOR WITH CAM ACTION 1. Field of the Invention This invention relates to electrical connectors, and in particular to fluid pressure controlled electrical connectors for force-free insertion and removal of terminals of electrical devices.

2. Description of the Prior Art Fluid pressure controlled connectors or sockets for electrical devices are known as illustrated by US. Pat. Nos. 2,978,666 and 3,366,916. In general, these devices may be hydraulically or pneumatically controlled to selectively position resilient segments or jaw members to provide either zero or nominal insertion force. This is normally accomplished by means of suitable spaced resilient tubing sandwiching the contact segments between them which are initially positioned in an open position to provide either zero or nominal insertion and removal force on contact terminals of an electrical device for interconnection to complementing circuits or for test purposes.

After insertion in the socket, the resilient tubing is pressurized to inflation with a fluid to clamp the jaw members in a closed position about respective terminals, of an electrical device to make electrical and mechanical connection therewith. For removal of the inserted devices, the tubing is depressurized to permit the resilient jaw members to return to the open position whereby the device terminals may be removed without any substantial force. These fluid pressure controlled connectors enable the application of a uniform and controllable contact pressure without danger of deforming the inserted contact terminals of a device or removal of protective coating therefrom.

Although the use of such inflatable tubing in these connectors provides the desired uniform pressure for electrical and mechanical connection, there an inherent disadvantages, upon depressurization, of a tendancy of the tubing to set in the inflated position in addition to the natural inertia of the tubing to deflate. The features limit quick recovery of the jaw members, and detract from the accuracy of subsequent positioning for insertion of additional devices in the socket.

SUMMARY OF THE INVENTION The present invention comprehends an electrical connector or socket normally containing a-plurality of resilient contact elements having spaced actuable female contact members or segments for releasably receiving terminal contacts of an electrical device, as for example terminal tabs of a printed circuit card, terminal pins of modules or other electrical elements, and the like. The female members or segments of the contact are normally biased in the open position in a spacing sufficient to permit substantially force-free insertion of an electrical device for testing purposes or for interconnection to complementing circuits. Each set of the spaced resilient contact members or segments are slidably mounted in a corresponding aperture of a reciprocable cam plate normally biased adjacent the bight of the members to maintain them in the open posi tion. A fluid pressure responsive member is associated with the cam plate for driving the cam plate along the extension of the contact segments to deflect them inwardly of each other into a closed position in mechanical and electrical connection about inserted terminal contacts of an electrical device. Suitable bias means is also associated with the cam plate to return it to its initial position to permit the contact segments to spring back in the open position.

Accordingly, it is an object of this invention to provide an improved electrical connector.

It is another object of this invention to provide an electrical socket or connector for substantially force-free insertion and removal terminal leads of an electrical device, and adapted to make uniform electrical and mechanical connection thereto.

The foregoing and other objects, features and advantages of the invention will be more apparent from the following more particular description of the embodiments of the invention, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS in the drawings;

FIG. 1 is an elevational view of one embodiment of this invention shown in association with a printed circuit board prior to the insertion thereof in this embodiment of the connector;

FIG. I A is a fragmentary view taken along line lA-IA of FIG. 1;

FIGS. 2 and 3 are cross-sectional views taken along line 2-2 of FIG. 1 showing various stages in the operation of this embodiment of the invention;

FIG. 3A is a fragmentary view taken along line 3A-3A of FIG. 3;

FIGS. 4 and 5 are cross-sectional views illustrating various stages in the operation of another embodiment of this invention; FIGS. 6 and 7 are cross-sectional views illustrating various stages in the operation of a further embodiment of this invention; and t FIG. 8 is an exploded view in perspective of an additional embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, FIGS. 1 to 7 illustrate the application of the inventive concept to an edge connector for a printed circuit card or board 2 having spaced terminal tabs 3 for insertion into corresponding opening 4 of a card connector or socket l. The printed circuit board 2 has a conductive circuit pattern 5 terminating in the terminal contacts 6 on the circuit board tabs 3.

The connector 1 comprises a connector block of dielectric material such as nylon, Teflon, melamine and the like which may be suitable formed by casting, molding or by other techniques known in the art.

Mounted in the connector are a plurality of contact elements 7 mounted in spaced-apart longitudinal alignment, with connector openings 4, along the connector for registered connection with the terminal contacts 6 of printed circuit board 2. Each of the contact elements 7 is mounted in a baseplate 8, of the connector, by means of a shank portion 9 extending through an associated plate aperture 10 and terminating in a contact lug 11 for connection to an external complementing circuit. The contact element 7 includes two bifurcated resilient female members or segments 12 and 13 of spring stock material, such as thin strip stock beryllium copper, diverging from a common bight 14 in sufficiently spaced-apart relations to define a normally open position for force-free insertion of the terminal tabs 3 of the circuit board 2.

The connector baseplate 8 is formed with a recess 15 provided with a fluid access groove 16 communicating with the fluid port 40. In the preferred form, the plate recess 15 is formed with vertical walls and circumscribes all contact elements 7 as part of a reversibly expansible chamber 17 during either pneumatic or hydraulics pressurization with a suitable fluid such as airv or water, respectively.

Telescopically mounted within the baseplate recess 15 is an inverted cup-shaped piston defined by a pair of spaced skirt or wall members 18 and 19 depending downwardly from a cam plate 20. Cam plate 20 is normally biased adjacent base 8 by a serpentine leaf spring 21 mounted within the connector I in recessed seats 22 and 23 between, respectively, the cam plate 20 and a recessed member 24 which is suitably secured to baseplate 8 by fasteners 25. Cover member 24 is provided with a plurality of openings 4 in register with contact elements 7 for receiving the circuit card tabs 3.

Cam plate 20 is provided with a plurality of spaced longitudinally aligned apertures 30 for slidably mounting about respective ones of the contact elements 7 and normally biased adjacent the bights 14 thereof by spring 21 to maintain the spaced female members or contact segments, 12 and 13 in their normally open position.

In operation, the tabs 3 of circuit board 2 are inserted, with substantial zero or nominal insertion force, through socket openings 4 between a corresponding pair of spaced contact segments 12 and I3 maintained in their normally open position. After insertion of circuit board 2 into socket or connector 1, the expansible chamber 17 of the latter is pressurized with air or other fluid via port 40 to, during extension of chamber 17, drive cam plate 20 upwardly against spring 21. As cam plate 20 moves upwardly, the apertures thereof traverse the contact segments 12 and 13 to deflect them inwardly of each other into a closed position to make mechanical and electrical contact with the terminal portions 6 and 6A of circuit on board 2.

For removal of the circuit board 2, the pressure within the exposable chamber 17 is released, whereby spring 21 returns cam plate 20 to its normally bottomed position to permit the resilient contact segments 12 and 13 to spring back to their normally open position for substantially force-free removal of circuit card 2 from connector 1.

FIGS. 4 and 5 show a modification of the connector or socket ll of the preceding embodiment in which the expansible chamber 17 thereof is replaced with a collapsed inflatable member 17A which may be in the form of a tube of resilient material such as any of the various natural or synthetic rubbers. In this modification, the cup-shaped member (defined by skirts 18 and 19) is eliminated and the recess forms a seat 15A for positioning the inflatable member 17 A with suitable fluid pressure to drive cam plate A upwardly against spring 21. As in the preceding embodiment, release of fluid pressure within tube 17A enables spring 21 to bottom cam plate 20A to permit the resilient contact segments 12 and 13 to spring back in the open position for removal of circuit board 2.

FIGS. 6 and 7 show a further modification of this invention in which the coaction between the bias spring 21 and expansible chamber r 17 of the embodiment of FIGS. 2 and 3 is reversed. In this modification, a recess component for an extensible chamber 173 is formed in the cover member 24A and telescopically receives a cup-shaped member defined by upstanding skirts 18A and 19A formed on the upper surface of cam plate 20B. In turn, bias springs 21A are mounted between cam plate 208 and a baseplate 8B. In this embodiment, springs 21A normally bias cam plate 208 in the upward position to position the apertures thereof at the upper portions of the contact segments 12 and 13 for normal inward deflection thereof in a closed position.

In operation, for insertion or removal of a circuit board 2, the expansible chamber 178 is extended by suitable pressurization thereof by a fluid via port 40A to drive cam plate 20A downwardly against spring 21A. As cam plate 20A is positioned adjacent the bight 14 of contact segments 12 and 13, they spring outwardly into the open position. After insertion of a circuit board 2 into connector 1B, the pressure is released with subsequent biasing of cam plate 20B into its normally upward position by spring 21A. As the cam plate 20A moves upwards, the traverse of the apertures thereof along contact segments 12 and 13 deflects them inwardly in the normally closed position in electrical and mechanical contact with the terminal contacts 6 and 6A on the tab portions 3 of circuit board 2.

FIG. 8 shows a further embodiment of this invention in which the connector 38 is adapted for receiving an array of terminal pins 35 depending on a module 36 or other electrical device. Also provided in this embodiment is a matrix of con; tact elements 7A suitable embedded in a baseplate 8C and having external projecting pin portions 37 for insertion into a main panel board of a test system or other complementing circuits. As in the previous embodiments, each contact elernent 7A is formed with resilient bifurcated contact segments 12 and 13 diverging into spaced relationship from a common bight 14.

An expansible chamber 17C is defined in part by an annular recess 15D defined by vertical walls, and having formed in the bottom wall thereof a radial fluid access groove 16C communication with inlet 41 via a fluid port 40B for connection to a suitable source of fluid pressure.

Telescopically mounted in annular recess ISD is an annular cup-shaped member defined by annularly spaced skirts 18B and 19B depending downwardly from a cam plate 20C provided with an array of apertures 30A for mounting about a respective one of the array of contact elements 7A.

Formed in the upper face of cam plate 20C is a recessed seat 22B for a compression coil spring 213 also seated in a recess 238 in cover member 248 which is secured to baseplate 8C by suitable fasteners 25. When assembled, coil spring 2113 biases cam plate 20C against baseplate 8C adjacent bight 14 of their respective contact segments 12 and 13 of each contact element. In this position of cam plate 20C, each set of resilient contact segments 12 and 13 are maintained in spaced apart position defining their normally open position for receiving a respective one of module pins 35 depending from module 36.

After insertion of module 36 in connector 38, its chamber 17C is pressurized via inlet 41 with a suitable fluid, such, as air, to drive cam plate 20C upwardly against compression spring 218 and thereby close contact segments 12 and 13 in mechanical and electrical connection against a respective module pin 35 as the cam apertures 30A are traversed upwardly along the various sets of contact segments 12 and 13.

As in the preceding embodiments, with release of pressure in the connector chamber 17C, compression springs 21B drive cam plate 20C against baseplate 8C and adjacent the contact bights 14 to free the contact segments 12 and 13 which spring back to their open position enabling force-free withdrawal of module 36.

While the invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

I claim:

1. An electrical connector comprising:

A. a support;

B. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments:

a. extending in spaced relationship;

b. having a common bight portion adjacent said support;

and

0. adapted for connection to an external circuit; bight C. a cam plate having an aperture mounted about said contact segments adjacent said bight thereof:

a. with said contact segments in their said spaced relationship defining an open position; and

b. with said cam plate adapted for sliding movement along the extension of said contact segments adjacent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position;

D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: i

E. an expansible member intermediate said cam plate and said support and including; i

F. a second means for selectively pressurizing and depressurizing said expansible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said expansible member is pressurized; and

G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said expansible member is depressurized.

2. An electrical connector comprising:

A. a support;

B. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments:

a. extending in spaced relationship;

b. having a common bight portion adjacent said support;

and

c. adapted for connection to an external circuit;

C. a cam plate having an aperture mounted about said contact segments adjacent said bight thereof:

a. with said contact segments in their said spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of said contact segments adjacent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position; and I D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: E. an extensible member intennediate said cam plate and said support; and including F. second means for extension and retraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is retracted; and wherein said extensible member comprises a reversibly extensible chamber comprising: H. a recess in said support peripherally circumscribing said contact element; and l. a pair of spaced wall members;

a. dependingfrom said cam plate; b. peripherally circumscribing said contact element; and c. slidably mounted in said recess in telescoping relationship therein; and wherein J. said second means includes means for pressurizing and depressurizing said chamber for, respectively, extending and contracting said chamber in response to the reaction of said cam plate to said bias means. 3. An electrical connector comprising: A. a support; 8. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments: a. extending in spaced relationship; b. having a common bight portion adjacent said support;

and 0. adapted for connection to, an external circuit; C. a cam plate having an aperture mounted about said contact segments adjacent said bight thereof: a. with said contact segments in their said spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of said contact segments adjacent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position; and D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: B. an extensible member intermediate said cam plate and said support; and including F. second means for extension and retraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is retracted; and wherein said extensible member comprises: H. a recess in said support peripherally circumscribing said contact element; and l. a piston element a. depending from said cam plate; b. peripherally circumscribing said contact element; and c. slidably mounted in said recess in extensible relationship therein; and

J. wherein said second means includes means for pressurizing and depressurizing said member intermediate said piston and said recess for, respectively, extending and retracting said piston in response to the reaction of said cam plate to said bias means.

4. An electrical connector comprising:

A. a support;

B. a plurality of spaced contact elements mounted to said support, with each said elements comprising:

a. female contact segments spaced apart in diverging relationship;

b. having a common bight portion adjacent said support;

c. adapted for connection to an external circuit;

C. a cam plate having openings corresponding to and in register with said contact elements;

a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said contact segments in their spaced relationship defining an'open position; and

b. with said cam plate adapted for sliding movementalong the extension of contact segments adjacent the end portions thereof for deflecting a mounted contact segments inwardly of each other to define a closed position; and i D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions wherein E. said means comprises an expansible member intermediate said cam plate and said support; and including F. a second means for selectively pressurizing and depressurizing said expansible member whereby said cam plate is driven toward and adjacent said end portion of said contact segments for positioning thereof in a closed position when said expansible member is pressurized; and

G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments to position the contact segments in the open position when said expansible member is depressurized.

5. An electrical connector comprising:

A. a support;

B. a plurality of spaced contact elements mounted to said support, with each said elements comprising:

a. female contact segments spaced apart in diverging relationship;

b. having a common bight portion adjacent said support;

0. adapted for connection to an external circuit;

C. a cam plate having openings corresponding to and in register with said contact elements;

a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said'contact segments in their spaced relationship defining an open position; and

b. with said cam plate adapted for sliding movement along the extension of contact segments adjacent the end portions thereof for deflecting a mounted contact segments inwardly of each other to define a closed position; and

D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions; wherein B. said means comprises an extensible member intermediate said cam plate and said support; and including F. second means for extension and contraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and

G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is contracted; and wherein said extensible member comprises a reversibly extensible chamber comprising:

H. a recess in said'support peripherally circumscribing said contact element; and l. a pair of spaced wall members a. depending from said cam plate;

b. peripherally circumscribing said contact element; and

c. slidably mounted in said recess in telescoping relation ship therein; and

J. wherein said second means includes means for pressurizing and depressurizing said chamber for, respectively, extending and contracting said chamber in response to the reaction of said cam plate to the last said means and said bias means.

6. An electrical connector comprising:

A. a support;

B. a plurality of spaced contact elements mounted to said support, with each said elements comprising:

a. female contact segments spaced apart in diverging relationship;

b. having a common bight portion adjacent said support;

c. adapted for connection to an external circuit;

C. a cam plate having openings corresponding to and in register with said contact elements;

a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said contact segments in their spaced relationship defining an open position; and

b. with said cam plate adapted for sliding movement along the extension of contact segments adjacent the end portions thereof for deflecting a mounted contact segments inwardly of each other to define a closed position; and

D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions; wherein E. said means comprises an extensible member intermediate said cam plate and said support; and including F. second means for extension and contraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and

G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is contracted; and wherein said extensible member comprises:

H. a recess in said support peripherally circumscribing said contact element; and

l. a piston element a. depending from said cam plate; b. peripherally circumscribing said contact elements; and c. slidably mounted in said recess in extensible relationship therein; and

J. wherein said second means includes means for pressurizing and depressun'zing said member intermediate said piston and said recess for, respectively, extending and retracting the piston in responseto the reaction of said cam plate to the last said means and said bias means. 

1. An electrical connector comprising: A. a support; B. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments: a. extending in spaced relationship; b. having a common bight portion adjacent said support; and c. adapted for connection to an external circuit; bight C. a cam plate having an aperture mounted abOut said contact segments adjacent said bight thereof: a. with said contact segments in their said spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of said contact segments adjacent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position; D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: E. an expansible member intermediate said cam plate and said support and including; F. a second means for selectively pressurizing and depressurizing said expansible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said expansible member is pressurized; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said expansible member is depressurized.
 2. An electrical connector comprising: A. a support; B. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments: a. extending in spaced relationship; b. having a common bight portion adjacent said support; and c. adapted for connection to an external circuit; C. a cam plate having an aperture mounted about said contact segments adjacent said bight thereof: a. with said contact segments in their said spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of said contact segments adjacent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position; and D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: E. an extensible member intermediate said cam plate and said support; and including F. second means for extension and retraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is retracted; and wherein said extensible member comprises a reversibly extensible chamber comprising: H. a recess in said support peripherally circumscribing said contact element; and I. a pair of spaced wall members; a. depending from said cam plate; b. peripherally circumscribing said contact element; and c. slidably mounted in said recess in telescoping relationship therein; and wherein J. said second means includes means for pressurizing and depressurizing said chamber for, respectively, extending and contracting said chamber in response to the reaction of said cam plate to said bias means.
 3. An electrical connector comprising: A. a support; B. a bifurcated contact element mounted to said support comprising a pair of resilient female contact segments: a. extending in spaced relationship; b. having a common bight portion adjacent said support; and c. adapted for connection to an external circuit; C. a cam plate having an aperture mounted about said contact segments adjacent said bight thereof: a. with said contact segments in their said spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of said contact segments adjaCent the end portions thereof for deflecting said contacts segments inwardly of each other to define a closed position; and D. means for controllably reciprocating said cam plate between said bight and said end portions of said contact segments for selective positioning thereof in the open and closed positions; wherein said means comprises: E. an extensible member intermediate said cam plate and said support; and including F. second means for extension and retraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is retracted; and wherein said extensible member comprises: H. a recess in said support peripherally circumscribing said contact element; and I. a piston element a. depending from said cam plate; b. peripherally circumscribing said contact element; and c. slidably mounted in said recess in extensible relationship therein; and J. wherein said second means includes means for pressurizing and depressurizing said member intermediate said piston and said recess for, respectively, extending and retracting said piston in response to the reaction of said cam plate to said bias means.
 4. An electrical connector comprising: A. a support; B. a plurality of spaced contact elements mounted to said support, with each said elements comprising: a. female contact segments spaced apart in diverging relationship; b. having a common bight portion adjacent said support; c. adapted for connection to an external circuit; C. a cam plate having openings corresponding to and in register with said contact elements; a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said contact segments in their spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of contact segments adjacent the end portions thereof for deflecting a mounted contact segments inwardly of each other to define a closed position; and D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions; wherein E. said means comprises an expansible member intermediate said cam plate and said support; and including F. a second means for selectively pressurizing and depressurizing said expansible member whereby said cam plate is driven toward and adjacent said end portion of said contact segments for positioning thereof in a closed position when said expansible member is pressurized; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments to position the contact segments in the open position when said expansible member is depressurized.
 5. An electrical connector comprising: A. a support; B. a plurality of spaced contact elements mounted to said support, with each said elements comprising: a. female contact segments spaced apart in diverging relationship; b. having a common bight portion adjacent said support; c. adapted for connection to an external circuit; C. a cam plate having openings corresponding to and in register with said contact elements; a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said contact segments in their spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of contact segments adjacent the end portions thereOf for deflecting a mounted contact segments inwardly of each other to define a closed position; and D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions; wherein E. said means comprises an extensible member intermediate said cam plate and said support; and including F. second means for extension and contraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is contracted; and wherein said extensible member comprises a reversibly extensible chamber comprising: H. a recess in said support peripherally circumscribing said contact element; and I. a pair of spaced wall members a. depending from said cam plate; b. peripherally circumscribing said contact element; and c. slidably mounted in said recess in telescoping relationship therein; and J. wherein said second means includes means for pressurizing and depressurizing said chamber for, respectively, extending and contracting said chamber in response to the reaction of said cam plate to the last said means and said bias means.
 6. An electrical connector comprising: A. a support; B. a plurality of spaced contact elements mounted to said support, with each said elements comprising: a. female contact segments spaced apart in diverging relationship; b. having a common bight portion adjacent said support; c. adapted for connection to an external circuit; C. a cam plate having openings corresponding to and in register with said contact elements; a. with each opening mounted about the contact segments of its corresponding contact element adjacent the bight thereof with said contact segments in their spaced relationship defining an open position; and b. with said cam plate adapted for sliding movement along the extension of contact segments adjacent the end portions thereof for deflecting a mounted contact segments inwardly of each other to define a closed position; and D. means for controllably moving said cam plate between said bight and said end portions of each said contact segments for selective positioning thereof in the open and closed positions; wherein E. said means comprises an extensible member intermediate said cam plate and said support; and including F. second means for extension and contraction of said extensible member whereby said cam plate is driven toward and adjacent said end portions of said contact segments for positioning thereof in a closed position when said extensible member is extended; and G. bias means for yieldingly urging said cam plate toward said support adjacent said bight of said contact segments for positioning thereof in the open position when said extensible member is contracted; and wherein said extensible member comprises: H. a recess in said support peripherally circumscribing said contact element; and I. a piston element a. depending from said cam plate; b. peripherally circumscribing said contact elements; and c. slidably mounted in said recess in extensible relationship therein; and J. wherein said second means includes means for pressurizing and depressurizing said member intermediate said piston and said recess for, respectively, extending and retracting the piston in response to the reaction of said cam plate to the last said means and said bias means. 